tabes is in many cases a symptom-complex, pointing to a disease of the posterior roots, which disease is not a primary one, but a secondary, coming on, as in Bennett's case, from the pia mater.

This observation is interesting also in many other regards: (1) It completely confirms our view that discussing tabetic appearances it is always necessary to take into consideration the condition of the posterior roots, of investing membranes, etc., and in the thorough study of each separate case, and especially of cases similar to the above described, an objective observer will come to the conclusion that in many, if not in all cases, tabes dorsalis is only a symptom of some disease of the posterior spinal roots or membranes, like the case of Dr. Bennett, where tabes dorsalis was only a symptom of sarcoma of the lumbar region of the spinal cord. Cases similar to the above make us always remember that in discussing the question of the aetiology we must bear in mind the possibility of occasional ætiological factors, as tumors of the roots or membranes. Processes in the latter must inevitably influence one way or another the posterior roots and their prolongations-posterior columns; therefore the condition of the membranes must play a prominent part in the ætiology of tabes, i. e., everything producing affection of the spinal membranes leads also to the affection of the posterior roots and can give as a result the picture of tabes.

The causes, however, of membrane affections, acute as well as chronic ones, as is known, are: (a) Infectious diseases, as typhoid fever,* syphilis; (b) exposure to cold and (c) sexual excesses; these three causes were proposed, as we saw, as chief causes also of tabes dorsalis.

The most common and frequent cause of the affection of the spinal membranes is syphilis; therefore we find it most often among the etiological factors of tabes.

*Martius: Ueber iinen Fall von Tab. dorsalis (the cause typhoid fever).—Deut. med. Woch., 1888, pp. 163-165.

was here

Each of the above-mentioned theories can be held as correct in the etiology of tabes dorsalis as long as they are held correct in the question of the origin of meningitis. "Accepting the latter as the cause of tabes," says Erb, “we can understand the development of tabes under the influence of long marches, colds, etc.

Discussing the question of the treatment of any disease we must always take into consideration its ætiology. In tabes we have always to do with one ætiological factor-compression of the posterior roots; other ætiological factors, such as the above-named, must also be borne in mind, inasmuch as they continue to play a part in its further development. However it may be, if tabes is a result of the mechanical compression on the part of the roots, it is clear that the removal of this compression must be the first and chief purpose of the treatment.

If this compression consists in a tumor, compressing the posterior roots, the single rational treatment is an operation, as it was first performed on the spinal cord, on another account, by Prof. Horsley.

If the cause is chronic meningitis, with the formation of fibrous connective tissue around the roots, the removal of the compression from the roots by means of operative methods would seem also most rational.

As long as experimental investigations in this direction are not performed, it is impossible to make any other propositions on this account and the therapy must consist in the removal of the remote cause-meningitis; namely,. everything that appears useful in the treatment of the latter must. be also useful in the treatment of tabes, because in our opinion tabes is only a form of meningitis. Therefore, different blood-letting methods of treatment, as, for instance, points de feu, Spanish flies on the vertebral columns, electricity or massage give and must give in some cases good results.

Good results must be and sometimes are really obtained by suspension of tabetic patients according to Motshutkovsky's

method, because suspension of the vertebral column, stretching the latter, as it is believed, distend at the same time the spinal membranes, thus liberating the roots from the compression or diminishing the latter. The fact that everything acting well on meningitis produce sometimes good effects on tabes, confirms again the correctness of our opinion that tabes in most cases is a consequence of meningitis or a form of meningitis.

It is apparent at the same time that no operative methods with distension of nerves, no remedies (pharmaceutical preparations) as argentum nitricum, no organotherapy with feeding of tabetic patients with sheep's brains, can give good results in the treatment of tabes.

Only one method may be beneficial in the treatment of tabes dorsalis, this is the artificial liberation of the posterior roots from their compression. It is true that once degenerated fibers cannot become regenerated, as the fibers of the posterior columns once cut through cannot become regenerated (Eichorst, Naunyn, Schiff), but by the removal of the compression from the roots in the earliest periods of the disease we can stop its further development, which must be the chief purpose of treatment in tabes.

In cases of cerebral tabes the operative methods are not applicable, but these forms of tabes take a favorable course and do not need any active interference.

All these are only theoretical considerations, which are to be confirmed by experiments on animals. These must consist in the artificial production of tabes, its artificial removal by way of an operation, etc., etc., which experiments are very desirable even for the reason that they can help the understanding of such a common and obstinate disease as tabes dorsalis and at the same time elaborate rational methods of treatment.

In conclusion I will point out the following:

(1) Tabes dorsalis is the product of affection of the posterior roots of the spinal cord.

(2) This affection is chiefly a mechanical one, owing chiefly to the compression on the part of the membranes of the spinal cord or of the brain.

(3) The cause of tabes is everything that may produce. meningitis, i. e., taking cold, sexual abuses and infectious diseases, of which the chief is syphilis.

(4) The treatment, according to conclusion 2, must be a mechanical one, i. e., surgical in those forms of tabes where it can be applied (tabes cervicalis, tabes dorsalis).

(5) Such a treatment undertaken in the earliest periods of the disease can and must stop its further development.

(6) In studying the clinical forms of tabes it is necessary to apply all the newest methods applicable in the study of meningitis: Körnig's symptom, cryoscopy, cytoscopy and hæmolysis of the spinal fluid of tabetic patients.

(7) Minutest microscopical examination of the spinal membranes and the brain are necessary.

(8) For the purpose of explaining the pathology of this disease and its therapeutical methods there are necessary new clinical as well as pathologico-anatomical observations, and above all experiments on animals.

SEMILUNAR CARTILAGES; THEIR ANATOMY AND SURGERY.-By H. A. SIFTON, Professor of Clinical Surgery, Milwaukee College of Physicians and Surgeons, Milwaukee, Wis.

Anatomy. The semilunar interarticular fibro-cartilages are two in number, an inner and outer, placed horizontally between the articular surfaces of the femur and tibia. In general outline they correspond to the circumferential portions of the tibial facets upon which they rest. Each has a thick, convex, fixed border in relation to the periphery of the joint and a thin, concave, free border directed towards the interior of the joint. Neither of them is sufficiently large to cover the whole of the articular surface upon which it rests. The upper and lower surface of each semilunar is smooth and free and each cartilage terminates in an anterior and posterior fibrous horn. The internal semilunar fibro-cartilage forms very nearly a semi-circle. It is attached by its anterior horn to the non-articular surface on the head of the tibia in front of the tibial attachment of the posterior crucial ligament, and by its posterior horn to the non-articular surface immediately in front of the tibial attachment of the posterior crucial ligaThe external semilunar fibro-cartilage is attached by its anterior horn to the non-articular surface of the tibia in front of the tibial spine where it is placed to the outer side and partly under cover of the tibial end of the anterior crucial ligament. By its posterior, horn it is attached to the interval between the two tubercles which surmount the tibial spine. This fibro-cartilage with its two horns therefore forms almost a complete circle. The two horns of the external semilunar are embraced by the two horns of the internal one and while the anterior crucial ligament has its tibial attachment

ment.